The present invention relates to a probe for scanning probe lithography and a making method thereof.
As an integration scale of semiconductor devices and a density level of recording media have increased, it has been required to provide an advanced technique for microstructure fabrication thereof. At present, in photolithography process for production of common semiconductor devices, a minimum fabrication dimension is limited to approximately 100 nm due to characteristics of an optical wavelength of a light source and a material of a lens used in photolithography equipment. Further, in laser process for production of masters of recording media, a minimum fabrication dimension is approximately 200 nm, which might cause a decrease in margin of resolution.
In recent years, particular attention has been focused upon a microstructure fabrication technique based on scanning probe microscopy to be employed in lieu of the conventional art mentioned above, e.g., this technique is found in Journal of Vacuum Science Technology B4 (1986), pp. 86–88, reported by M. A. McCord et al. In the microstructure fabrication technique based on scanning probe microscopy, a voltage is applied between a probe and a substrate for forming microstructure patterns, and extremely high resolution is attainable to allow atomic-level or nanostructure fabrication in principle. In Journal of Vacuum Science Technology B6 (1988), pp. 293–296, reported by M. A. McCord et al., and in Applied Physics Letter 61 (1992) pp. 2293–2295, reported by A. Majumdar et al., there is disclosed a microfabrication process method of scanning probe lithography in which patterns are formed using a resist film as in conventional lithography. Since a well-established pattern transfer method for transferring patterns from a resist film to a substrate, which has been developed for the conventional lithography, is applicable to the scanning probe lithography, it is expected that the scanning probe lithography will find widespread use in practice of the next generation of microfabrication. In particular, a scanning probe lithography technique in which a micro-cantilever type of probe designed for an atomic force microscope is used and the exposure is controlled by varying a voltage for keeping a constant current flowing, as proposed by K. Wilder et al. in Journal of Vacuum Science Technology B15 (1997), pp. 1811–1817, has received considerable attention because of its advantageous controllability and reproducibility of uniform pattern linewidths.